ln-113-backend-docs-creator

SKILL.md

Paths: File paths (references/, ../ln-*) are relative to this skill directory.

Backend Documentation Creator

Type: L3 Worker

L3 Worker that creates 2 backend documentation files. CONDITIONAL - only invoked when project has backend or database.

Purpose & Scope

Creates api_spec.md (if hasBackend)

Creates database_schema.md (if hasDatabase)

Receives Context Store from ln-110-project-docs-coordinator

OpenAPI 3.0 compliant API specification

ER diagrams in Mermaid for database schema

Never gathers context itself; uses coordinator input

Invocation (who/when)

ln-110-project-docs-coordinator: CONDITIONALLY invoked when:

hasBackend=true (express, fastify, nestjs, fastapi detected)

hasDatabase=true (pg, mongoose, prisma, sequelize detected)

Never called directly by users

Inputs

From coordinator:

contextStore: Context Store with backend-specific data

API_TYPE (REST, GraphQL, gRPC)

API_ENDPOINTS (from route scan)

AUTH_SCHEME (JWT, OAuth2, API keys)

DATABASE_TYPE (PostgreSQL, MongoDB, MySQL)

SCHEMA_OVERVIEW (from migrations/models)

ER_DIAGRAM (generated from schema)

targetDir: Project root directory

flags: { hasBackend, hasDatabase }

MANDATORY READ: Load references/docs_quality_contract.md, and references/markdown_read_protocol.md.
Optional rule catalog: load references/docs_quality_rules.json only when exact rule IDs, path matrices, or allowlisted placeholder exceptions are needed.

Documents Created (2, conditional)

File
Condition
Questions
Auto-Discovery

docs/project/api_spec.md
hasBackend
Q39-Q40
Medium

docs/project/database_schema.md
hasDatabase
Q41-Q42
High

Workflow

Phase 1: Check Conditions

Parse flags from coordinator

If !hasBackend && !hasDatabase: return early with empty result

Determine which documents to create

Phase 2: Create Documents

For each applicable document:

Check if file exists (idempotent)

If exists: skip with log

If not exists:

Copy template

Replace placeholders with Context Store values

Preserve the shared opening contract and standard top sections from the template

Generate ER diagram for database_schema.md

Never leave template markers in published backend docs

If data is missing: omit the claim or use a concise neutral fallback, but do NOT emit [TBD: ...]

Phase 3: Self-Validate

Check SCOPE tag and metadata markers

Check required top sections (Quick Navigation, Agent Entry, Maintenance)

Validate format:

api_spec.md: endpoint table, request/response examples

database_schema.md: ER diagram, table definitions

Check docs-quality contract compliance (no forbidden placeholders, no leaked template metadata, valid doc kind/role)

Phase 4: Return Status

{
  "created_files": ["docs/project/api_spec.md"],
  "skipped_files": ["docs/project/database_schema.md"],
  "quality_inputs": {
    "doc_paths": ["docs/project/api_spec.md", "docs/project/database_schema.md"],
    "owners": {
      "docs/project/api_spec.md": "ln-113-backend-docs-creator",
      "docs/project/database_schema.md": "ln-113-backend-docs-creator"
    }
  },
  "validation_status": "passed"
}

Critical Notes

Conditional: Skip entirely if no backend/database detected

OpenAPI compliant: api_spec.md follows OpenAPI 3.0 structure

ER diagrams: Generated in Mermaid erDiagram format

Idempotent: Never overwrite existing files

Publishable output: No [TBD: ...], TODO, or leaked template metadata in backend docs

NO_CODE_EXAMPLES Rule (MANDATORY)

API spec documents contracts, NOT implementations:

ALLOWED in api_spec.md: JSON request/response schemas (this IS the API contract), endpoint tables

FORBIDDEN: Controller implementations, validation classes, service code, middleware examples

TEMPLATE RULE: api_spec_template.md includes <!-- NO_CODE_EXAMPLES: ... --> tag - FOLLOW IT

Stack Adaptation Rule (MANDATORY)

Links must reference stack-appropriate docs (Microsoft for .NET, MDN for JS)

API examples must match project stack (Express for Node.js, FastAPI for Python)

Format Priority (MANDATORY)

Tables (endpoints, schemas) > Mermaid (ER diagrams) > Lists > Text

Runtime Summary Artifact

MANDATORY READ: Load references/docs_generation_summary_contract.md

Accept optional summaryArtifactPath.

Summary kind:

docs-generation

Required payload semantics:

worker = "ln-113"

status

created_files

skipped_files

quality_inputs

validation_status

warnings

Write the summary to the provided artifact path or return the same envelope in structured output.

Definition of Done

 Conditions checked (hasBackend, hasDatabase)

 Applicable documents created

 ER diagram generated (if database_schema.md created)

 Self-validation passed (metadata markers, top sections, format)

 Actuality verified: all document facts match current code (paths, functions, APIs, configs exist and are accurate)

 Status returned

Reference Files

Templates: references/templates/api_spec_template.md, references/templates/database_schema_template.md

Questions: references/questions_backend.md (Q39-Q42)

Version: 1.2.0
Last Updated: 2025-01-12